Compacter de-aerator



1965 E. D. FLEMMING ETAL 3,223,026

COMPACTER DE-AERATOR 2 Sheets-Sheet 2 Filed May 22, 1962 United States Patent Gfitiee 3,223fi26 Patented Dec. 14, 1965 3,223,026 CGMPACTER DE-AERATOR Edward D. Flemming, Bellevue, and Frank Wislocker,

Seattle, Wash, assignors, by mesne assignments, to

Weyerhaenser Company, Tacoma, Wash a corporatron of Washington Filed May 22, 1962, Ser. No. 196,643 4 Claims. (Ci. Nil-9d) This invention relates to a new and useful concept in a de-aerator attachment for compacting rolls and more particularly to a tie-aerating mechanism which utilizes a system of moving surfaces above the nip of the rolls to relieve air from finely divided material which is being fed through said rolls.

It is frequently necessary to convert finely divided, powdery materials into coarser particles to improve handling or performance characteristics. The conversion of finely divided aspirin powder into tablet form is an example in the pharmaceutical industry. Fertilizer chemicals and molding powders are also desirably converted to coarser particles to provide reduced dust in handling, reduced bulk for shipment purposes, and to minimize Stratification of a powdered mixture of chemicals having different densities.

Converting molding powders or fertilizers into coarse particulates form is conveniently done by passing the powder between closely spaced parallel steel rolls, known generally as compacting rolls. It is particularly useful to compact molding powders into coarser particles for the reasons mentioned above, and additionally to remove entrained air from the powder to insure air-free molded products. For instance, an uncompacted epoxy molding compound powder may Weigh approximately 30 to 40 pounds per cubic foot. To avoid entrapping air in the mold, thus providing a defect, it is desirable to compress the powder so that the compound will weigh in the area of 95 to 110 pounds per cubic foot. Normally this problem is solved by feeding the finely divided compound or powder through the nip of a pair of compacting rolls. When properly compacted the powder emerges from between the compacting rolls in a sheet or flake form. The sheet or flakes can then be partially ground if necessary and screened to produce the desired particle sizes.

Compacting finely divided materials such as epoxy molding compound powders is accompanied by several problems. Air entrained in the powder obstructs the flow of powder into the nip and this reduces the production rate. Unless the air is vented at the nip flakes obtained from the compacting operation will be thin and usualy accompanied by a good many fines. As a consequence it is necessary to run the material through the compacting rolls as many as two to four times in order to obtain the desired flake thickness.

Compacting without venting of the air also requires that greater energy be applied to the compacting rolls and increases the temperature of the compacted product. This is detrimental to heat sensitive materials such as molding powders.

Experimentation with various means showed that forcing the powder through the compacting nip simply aggravated the problem. Thus it was necessary to discover some way in which the air could be relieved or vented from the area just immediately above the nip. t was finally found that a slowly moving surface above the nip was the best way in which to vent the air from this area. A number of ways of doing the venting were tried but it was discovered that a plurality of fingers moving back and forth along the length of the nip produced the best results. The moving surfaces provide a passageway through which the entrained air can escape.

In the preferred form of the present invention a plurality of fingers are fixed into the throat of the hopper into which the powder is fed. The fingers extend through the entire length of the hopper and move about a fixed point or fulcrum. The fingers terminate at their lower ends at a point which is roughly in the same plane as the top of the rolls. The upper end of the fingers are attached to a moving bar which is reciprocally moved in a horizontal direction by a simple crank mechanism. The connection of the fingers on both the horizontally reciprocating bar and the stationary pivot bar located in the throat of the hopper are such that said connections are fixed or stationary but non-rigid. The fingers are reciprocated through a small are at a relatively slow speed. It was found in using this device that air was so efficiently vented or relieved from the roll nip that large flakes were obtained in one pass through the rolls. The end result was to increase the rate through the compacter fourfold, to provide better flakes than had ever been obtained in a number of passes through older operations and to greatly increase the percentage of flakes.

Accordingly, it is an object of this invention to provide an improved apparatus for compacting finely divided material or powder whether it be into sheet, flake, briquet, tablet or pellet form.

Another object of this invention is to supply an in proved compacter de-aerator which requires a reduced number of passes of the finely divided material through the compacting rolls in order to produce the desired results.

Yet another object of this invention is to provide an.

improved compacter de-aerator which is rugged in construction, simple in design and inexpensive to manufacture.

Still another object of this invention is to provide an improved compacter de-aerator in which moving surfaces are positioned above the length of the roll nip in order to vent air from the area above the roll nip.

A further object of this invention is to supply an improved compacter de-aerator which is fully automatic in operation.

These, together with other objects and advantages which will become subsequently apparent, reside in the details of construction as more fully hereinafter described and claimed, reference being had to the accompanying drawings, forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

FIGURE 1 is a side elevational view of the compacter de-aerator of this invention with a portion of the sidewall of the hopper broken away in order to more clearly show details of construction;

FIGURE 2 is a side elevational view in section of this invention taken along the line 22 of FIGURE 1;

FIGURE 3 is a partial view in perspective of the lower end of the hopper and the manner in which the lower end of said hopper is sealed with relation to the rolls; and

FIGURE 4 is a diagrammatic view in plan showing how the fingers in the preferred embodiment appear with relation to the rolls and the roll nip.

Referring now to FIGURE 1, it will be seen that the compacting portion of this apparatus is comprised of two adjacent rolls generally designated by the number 10. Rolls 10 are for purposes of illustration about 18 inches in diameter and driven by horizontally disposed shafts 12 which are approximately 4 inches in diameter. The axes of the rolls 1i) lie in an approximately common horizontal plane. The position of the rolls is adjustable so that gap between the rolls can be narrowed or widened at will. The T olls may also touch as at point 14 on the roll surface. The rolls are from end to end about 9 inches long. Each edge of each roll surface is provided with an annular scarf 3 or rabbet to form a vertical offset surface 16 and horizontal offset surface 18. The offset surfaces 16 and 18 will be considered together as annular scarf 20. The annular offset surfaces 16 and 18 are each approximately inch deep.

It will be noted from the above discussion that the compacting surface portion of the rolls It) is approximately 7 /2 inches long. A hopper mechanism generally shown by the number 22 is provided immediately above the nip of the rolls to feed finely divided material thereto. Hopper 22 is designed so that it covers the contact area of rolls which make it approximately 7 /2 inches in one dimension. Said hopper also covers the roll surfaces from center point to center point, establishing an end to end dimension of about 18 inches. The hopper is in excess of inches high from top to bottom. The approximate lower half of the hopper is constructed with generally vertical end walls 24 and side walls 26. End walls 24, of course, form the smaller of the two dimensions. The lower edges of walls 24 and 26 terminate in the same plane, which plane is spaced slightly above the topmost point of rolls 10 as at line 28. The upper edges of walls 24 and 26 shown by line 30 mark the level at which the hopper begins to flare outwardly in conventional fashion. The upper portion of the hopper has outwardly sloping end walls 32 and outwardly sloping side walls 34.

Approximately halfway between the top edges 30 and the bottom edges 28 of the generally vertical end and side walls 24 and 26 is a supporting strap in the form of metal angle members around the outside of said end and side walls. End walls 24 are provided with angle members 36 and the side walls 26 are provided with angles 38.

In order to confine the finely divided material or powder being fed into the hopper to the comp-acting surfaces, it is necessary to seal the bottom of the hopper and the rolls together. As mentioned above, the side walls 26 of the hopper are aligned with the vertical offset surface 16 of the rolls 10. The lower end of each sidewall 26 is tightly fitted within a heavy sealing boot 40 and of suitable nonmetallic, sealing material such as rubber, nylon, Teflon or the like. Said sealing boots 40 extend across the full width of the hopper sidewalls 26. Said sealing boots 40 are so formed that they extend downwardly and into the scarf 20. It will be seen that said sealing boots 40 have a straight top edge 42, side edges 44, inner surfaces 40a, and curved edges 48 conforming to the radius of curvature of the offset surface 18. The extreme lower end of said sealing boot 4t) terminates as at 46 slightly below the contact line 14 between rolls 1%). Sealing boots 40 are attached to the frame of the compacte-r in a manner that allows them to be adjusted in all directions as necessary to achieve a uniform clearance between surfaces 48 and 18 and surfaces 40a and 16. In this way the finely divided material is confined to the length of the nip and is prevented from falling over the ends of the rolls.

In like manner sealing boots 50 are attached to the lower portions of end walls 24 in order to seal the roll surfaces against the escape of the powder. These sealing boots 50 also perform the function of scraping the roll surfaces to remove any adhering compacted material. Said sealing boots 50 are nothing more than rectangular slabs of a suit able sealing material such as rubber, nylon or Teflon. Said sealing boots 50, of course, do bear against the roll surfaces. For all practical purposes then, the finely divided material which is put into the hopper is confined at the lower end of said hopper to the rolls and in order to escape must go through the nip of the rolls.

Sealing boots 4% because of the greater area in which they must seal are substantially thicker than the sealing boots 50 which must only guard the ends of the compacting apparatus. The sealing boots 50 may be attached to the hopper walls by bolts or some other method which gives a rugged, reliable connection. The above description completes discussion of the basic compacting apparatus.

The de-aerating feature of this invention is comprised essentially of a plurality of elongated rigid fingers extending generally vertically down through the length or throat of hopper 22. A pivot bar 52 extends across the short dimension of the hopper and is anchored midway between end walls 24 by bolts to the angle straps 38 on the front and back side walls 26. The fingers 54, of which there are shown to be four in the preferred embodiment, are, for purposes of illustration, approximately 2 inches wide by A1 inch in thickness. Said fingers 54 extend from the top of the hopper to a point below the bottom edge 28 of said hopper and just below the line established by the top of rolls 10. As will be observed in FIGURE 1 and FIGURE 2, the wide dimension of fingers 54 is positioned at degrees to the line defined by the contact point 14 of the rolls.

FIGURES 54 are attached to pivot bar 52 in a nonrigid connection. Each of the bar-shaped fingers 54 has a hole cut therein. Resilient annular grommets 56 made of rubber or the like are mounted on pivot bar 52 and sleeves 58 are mounted over the annular grommets 56. Sleeves 58 in turn are rigidly anchored to the holes in fingers 54. Thus a stationary but resilient or non-rigid pivot point is provided for fingers 54. The annular grommets 56, of course, are spaced from each other and should be secured to pivot bar 52 in order to prevent their sliding or moving on said pivot bar.

The actuating mechanism for fingers 54 is a simple reciprocating bar attached to a conventional crank mechanism. A channel member 60 is placed across the side sloping walls 34 directly above and in line with the roll nip, the fingers 54 and the pivot bar 52. The base or web portion of said channel member 60 is faced upwardly. A series of upper rollers 62 are mounted in the channel members 60 between the side walls of said channel members 60 between the side walls of said channel. Associated with each upper roller 62 is a bottom roller 64. Thus, there is defined a series of sets of upper and lower rollers. Each set of rollers 62 and 64 is provided with a small space between said rollers. In this way reciprocating bar 66 may be inserted in and supported on and between the series of roller sets. The upper ends of fingers 54 are attached to said reciprocating bar 66 in the same manner in which the fingers are mounted on the pivot bar 52.

A crank support beam 68 is connected to one side wall 34 and the channel member 60 and extends horizontally away fro-m said one side wall 34 for about half the distance again of said channel member 60. The free end of support beam 68 is supported from its underside by strut 70 attached to the free end of beam 68 and running down to be connected to a hopper side strap 38.

The crank mechanism generally designated by reference number '72 is composed of a shaft '74 rigidly attach-ed to crank arm 76 which at the end thereof has pivot connection 78. Linkage arm 80 connects the pivot point 78 on crank arm 76 with one end of reciprocating bar 66 as at pivot connection 82. It can be seen that reciprocating bar 66 protrudes from one end of channel member 60 in the direction of crank mechanism 72. Only three sets of upper and lower rollers 62 and 64 have been shown in the preferred embodiment. Obviously, if the size of the compacter de-aerating device is larger, more sets may be required. It has been found sufiicient to place one set of upper and lower rollers on each side of the fingers and a third set near the crank end of said channel member 60. The crank mechanism should be driven by a varialble speed motor.

The reciprocating bar 66 is designed to carry the upper ends of the fingers through about a 10 degree are. Approximately reciprocations per minute through said 10 degree are have been shown to produce excellent results. Fingers 54 have been found to work effectively with their lower ends placed anywhere in the range of from about 4 inches above the roll nip to a point slightly above the topmost point of the rolls, or 9 to 10 inches above said nip. Best results are obtained when the fingers extend to a point illustrated as in FIGURES 1 and 2 'Fingers 54 do not require any specific shape. Round inch rod or pipe stock has been found to serve the purpose of the fingers. Obviously the dimensions mentioned in this specification are for illustration only and are considered to be non-limiting since the dimensions could vary quite widely, depending on the material being compacted and the size of the compacter de-aerator itself. Operation of the comp-acting rolls is accomplished by the reciprocation of the lower end of the fingers to relieve the air compressed from a powder a-s it is squeezed into the roll nip. Best results for compacting of finely divided material, whether it be for sheet, flake, pellet, tablet or briquet in final form, are obtained when the hopper is maintained almost full or powder. In this way, weight or force is brought to bear on material in the bottom of the hopper, thus permitting the rolls to drive said material into said nip more easily.

It has been found that it is not absolutely essential that the fingers move in a direction parallel to the roll nip as shown by the double-headed arrows 84, 83 and 90 in FIGURE 4. A reciprocating device for relieving air has been shown to work when moved back and forth in the direction of dash-dot arrow 86 in FIGURE 4. This alternative method of relieving the air is effective but does not give the optimum results as when the fingers are moved parallel to the nip. It will be recognized that the moving surfaces for venting the material might also move in a generally circular direction, at an angle to the roll nip or in a combination of directions. It is also contemplated that Where a plurality of fingers are employed said fingers may move in a combination of directions. It must also be appreciated that one moving surface has been demonstrated and found to work very effectively. Furthermore, a foraminous finger or fingers can be used with no impairment of the venting operation since the moving surface or surfaces create a passage through the depth of the powder for permitting air to escape.

In essence the method of de-aerating finely divided material being compacted between a pair of parallel rolls involves filling a receiver located immediately above the rolls with the material. The rolls are started and a moving surface is inserted down through the throat of the receiver through the powder. The end of the moving surface is located above the nip of the rolls and moved preferably back and forth above the line of the nip to permit ai which gathers above the nip to be vented to the atmosphere. The movement of the surface does not have to assume any definite pattern or direction so long as said movement is substantially continuous.

The foregoing is considered as illustrative only of the principle of this invention. Since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.

What is claimed is:

1. A compac-ter de-aerator apparatus comprising:

a pair of power-operated, rotatable compacting rolls mounted side-by-side with the axes thereof in an approximately common horizontal plane, each of said rolls being provided with an annular scarf on each side of the outer surface thereof; hopper means mounted above said rolls, a throat means extending from the lower portion of said hopper means to the area between said rolls for feeding material to be compacted between said rolls; sealing means mounted between the lower end of said throat means and the surface of said rolls to prevent the escape of the material to be compacted;

a pivot Ibar extending entirely across, entirely within,

and rigidly mounted in said throat means;

a plurality of finger means pivotally mounted on said pivot abr for venting air from said material to be compacted extending upwardly through the interior of said hopper means, the lower ends of said plurali-ty of finger means terminating above the nip of said rolls and below said pivot bar; means pivotally connected to the upper ends of each of said plurality of finger means for moving said plurality of finger means about said pivot bar.

2. A compacter dc-aerator as set forth in claim 1, to-

gether "with a variable drive means connected to said moving means for moving said plurality of finger means about said pivot bar.

3. A oompacter de-aerator apparatus in accordance with claim 1 wherein said pivot bar extends through an aperture in each of said plurality of finger means and resilient annular grommets are mounted on said pivot bar with sleeves mounted over each of said grommets with each of said sleeves rigidly anchored to said plurality of finger means.

4. A compacter de-aerator apparatus in accordance with claim 3 wherein said moving means for movng said plurality of finger means is an elongated bar mounted between rollers and extending through the upper ends of each of said plurality of finger means.

References Cited by the Examiner UNITED STATES PATENTS 127,400 5/1871 Wright 222-233 209,508 10/ 1878 Pat-tillo 222-233 XR 277,228 5/1883 Castle et a1 107-34 XR 290,485 12/1883 Sifert 107-34 XR 312,975 2/1885 Cottom 222-233 XR 354,319 12/ 1886 Jensen 107-17 447,072 12/ 1901 Huntley 222-196 XR 694,285 2/1902 Joyner et a1. 222-233 XR 746,236 12/1903 Baggaley 55 474 XR 746,255 12/ 1903 Baggaley 55-474 XR 746,261 12/ 1903 Baggaley 55-474 XR 1,177,854 4/1916 Garfield 107-17 1,324,508 1 2/1919 Leopold 222-233 XR 1,409,972 3/ 1922 Riley 2 22-226 1,497,772 6/ 1924 Conklin 222-233 XR 1,673,313 6/ 1928 Cornelius 222-233 XR 1,731,223 10/ 1929 Brady 55-474 XR 1,783,092 11/1930 Lewis 222-233 XR 1,948,021 2/ 1934 Burton 222-226 2,521,380 9/1950 Lichtenfels 55-295 XR 2,573,315 10/1951 Dericks. 2,576,620 11/ 1951 Martin 222-228 2,635,949 4/1953 Fenske et al 55-390 XR 2,675,304 4/195-4 Komarek. 2,675,768 4411954 Helm. 2,798,645 7/ 1957 Keen et al. 222-226 2,919,466 1/1960 Roemer -90 XR 2,998,623 9/1961 Lawson et al 107-10 XR 3,029,723 4/ 196 2 Schweer 107-90 XR 3,055,557 9/1962 Rowe et all 222-233 XR 3,062,393 11/1962 Bond 222-226 XR 3,151,187 9/1964 Comte 55-474 XR FOREIGN PATENTS 439,288 1/ 1925 Germany.

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HARRY B. THORNTON, Primary Examiner.

REUBEN FRIEDMAN, Examiner. 

1. A COMPUTER DE-AERATOR APPARATUS COMPRISING: A PAIR OF POWER-OPERATED, ROTATABLE COMPACTING ROLLS MOUNTED SIDE-BY-SIDE WITH THE AXES THEREOF IN AN APPROXIMATELY COMMON HORIZONTAL PLANE, EACH OF SAID ROLLS BEING PROVIDED WITH AN ANNULAR SCARF ON EACH SIDE OF THE OUTER SURFACE THEREOF; A HOPPER MEANS MOUNTED ABOVE SAID ROLLS, A THROAT MEANS EXTENDING FROM THE LOWER PORTION OF SAID HOPPER MEANS TO THE AREA BETWEEN SAID ROLLS FOR FEEDING MATERIAL TO BE COMPACTED BETWEEN SAID ROLLS; SEALING MEANS MOUNTED BETWEEN THE LOWER END OF SAID THROAT MEANS AND THE SURFACE OF SAID ROLLS TO PREVENT THE ESCAPE OF THE MATERIAL TO BE COMPACTED; A PIVOT BAR EXTENDING ENTIRELY ACROSS, ENTIRELY, WITHIN, AND RIGIDLY MOUNTED IN SAID THROAT MEANS; A PLURALITY OF FINGER MEANS PIVOTALLY MOUNTED ON SAID PIVOT BAR FOR VENTING AIR FROM SAID MATERIAL TO BE COMPACTED EXTENDING UPWARDLY THROUGH THE INTERIOR OF SAID HOPPER MEANS, THE LOWER ENDS OF SAID PLURALITY OF FINGERS MEANS TERMINATING ABOVE THE NIP OF SAID ROLLS AND BELOW SAID PIVOT BAR; MEANS PIVOTALLY CONNECTED TO THE UPPER ENDS OF EACH OF SAID PLURALITY OF FINGER MEANS FOR MOVING SAID PLURALITY OF FINGER MEANS ABOUT SAID PIVOT BAR. 